Crush the graham crackers into fine crumbs. One third of a box is usually one wrapped package. Mix in the cinnamon and set aside. Melt the butter in a large saucepan. Remove from heat and add vanilla and peanut butter and mix well. Add the powdered sugar and graham crackers. Stir until well combined; it will be a stiff dough. Pat the mixture into an ungreased 9x13 pan. Melt the chocolate chips on very low heat in a really heavy saucepan, or spread evenly in a glass pie plate and microwave at 30 seconds at a time, stirring after 30 seconds, until melted. Spread the melted chocolate over the peanut butter layer. Refrigerate for 1 hour before cutting.